I've definitely used CDRs that are >10 years old with no issue - but they've also been stored well and not handled much.
–
warrenSep 1 '09 at 11:53

> Rumors say CDs and DVDs won't remember your data longer than ten years. I heard 50-100 years for both of them, and this was back when each was still new (i.e., the manufacturing processes—*should*—have improved since then, leading to longer lifespans).
–
SynetechJul 28 '12 at 3:30

You might think about getting a docking station to go with that, so you can keep buying cheaper internal hard drives and still switch them around easily. Internal hard drives stack better, too.
–
drbyAug 28 '09 at 7:28

7

Are you sure you will still be able to read a contemporary hard drive in the future? For example, could you connect a 20 year old hard drive to a modern PC to read the data off it?
–
Matthew LockAug 28 '09 at 7:43

2

Ability to read current supports in the future is a big problem of backup, no matter the support. Solutions involves copy backups to newer technologies as soon as they appear and/or keep old systems alive just for the purpose of retrieving backups.
–
mouvicielAug 28 '09 at 9:33

3

@ Matthew Lock: there is no way, a hard disc will outlast optical media.
–
Molly7244Nov 16 '09 at 17:34

1

The other day I connected my last remaining PATA backup drive for testing. The spindle grease was beyond seized. While the data was more than likely fine, the drive had still effectively died in storage.
–
user346081Jul 14 '14 at 7:53

Regarding longevity, you'll probably accumulate data too fast for the media to be a problem. 7 years from now you might have enough DVD's to fill a couple Blu-rays. 7 more years and you'll have a stack of Blu-rays ready to consolidate on whatever the next big thing is.

To begin with, I do not recommend
CD-RW, DVD-RW, or DVD+RW media in any
form for permanent storage. This is
mostly a no-brainer, but those discs
are meant to be able to be changed
after burning, and they are simply
unsuitable for long-term archival
storage. I also do not recommend DVD-R
media due to DVD+R’s superior error
correction and burning control.

That said, I recommend Taiyo Yuden
media across the board. Taiyo Yuden
currently manufactures 52x CD-R, 16x
DVD-R, and 8x DVD+R media in normal
shiney silver, inkjet printable, and
thermal printable forms. Taiyo Yuden
may be one of the most expensive (if
not the most expensive), but their
media quality is unsurpassed.

A recent update shows he still affirms this position.

I thought I read somewhere that the Library of Congress uses MAM-A archival gold DVD's but considering the cost I stick with TY's. I usually purchase through http://www.rima.com, while McFarland recommends another vendor in his article.

The Optical Storage Technology
Association (OSTA) has published the
following longevity estimates for
recordable optical media:

Manufacturers' estimated recorded life
span.

CD-R: 50-200 years

CD-RW: 20-100 years

DVD+R: 30-100 years

DVD+RW: 30 years

BD-R 50+ years

So, chances are that you may not live long enough to prove these estimates wrong! :)

Now compare that to the average lifespan of a platter hard disk (2-10 years). Optical media win that contest hands down.

And then there is the good old stone tablet which will last a couple of thousand years. But the data density of 0.001 kbit/kg is a bit of a showstopper. :P

But in IT, the Cranberry Diamondisc DVD is considered to be the Holy Grail of long term storage, they boast a life span 1000 (one thousand) years. Of course it requires special hardware to burn these discs.

YMMV of course, and only one set of backups isn't the best strategy anyway. but recommending platter HDDs instead of optical media because they last longer is plain wrong, they're cheap and fast alright but they're not really a choice for long term storage. they are no match for the longevity of CDs or DVDs. even magnetic tape lasts 6 times longer than the average life span of a hard disk.
–
Molly7244Nov 16 '09 at 17:21

hard disks being used or hard disks written to, disconnected, and put in a labelled box?
–
Paul NathanNov 16 '09 at 17:43

2

i don't think that there is much of a difference, it's probably worse if you don't fire up the discs every now and then, corrosion being its worst enemy. hard discs aren't really made for long term storage.
–
Molly7244Nov 16 '09 at 18:32

I'm not sure hard drives are any better than CD/DVD long term. The only way to be really sure is to keep checking the data and refreshing it. There are CD's/DVD's that are specifically designed for long term storage but as always these are more expensive.

I think it has to do with how much you're willing to spend. I've thought about this in the past and the best solution I could come up with was a NAS with 2 large HDDs in RAID 1 configuration. This way you're protected from HDD failure and I'm pretty sure that Ethernet will still be around 10 years from now. Only worry is if the NAS itself breaks down, so you'd need a quality one.

HP magneto-optical rewritable
cartridges allow virtually unlimited
read/write cycles, making them the
ideal choice for data management in
information-intensive environments. HP
write-once cartridges are designed for
permanent storage of data that can't
be altered or erased. Both disk
formats have an archival life of 100
years...

I think the question that must be asked is "how long-term is long-term"?

Quality paper is probably the most efficient low-end long-term storage currently known(300+ years).

But if you're looking to archive records in the event of nuclear blast, you might try etchings on metal in a can in a cave.

But if you want to store company records for 50 years, hard disks disconnected and stored in a vibration-less environment together with paper documents on the interface & data formats is not a bad plan.

But if you want to publish historical-class data for the next 200 years, ie, you're investigating for a library or similar institution, you want to make sure that the information is usable when we go to The Hypernet, so you might be investigating a redundant array of cloud data storage centers from different companies with a common query-able interface published on the current Internet.

But if you want to archive historical-class data, you want something that is probably similar to a ROM-style hard disk. (I'm taking a guess that those exist for long-term archive storage).

But are you storing text? video? pictures? binaries? Each of those has different information characteristics and can be stored a little differently.

USB flash drive- I sill have one 129 MB survived after washing in a machine and after all these years still works. When you start feeling that USB standart start to disapear or speed start to differ too much (i.e. USB 5.0 is the current standart)- transfer to the next new thing before is too late

The only way to guarantee long life is via redundancy. Keep 2 backup copies of everything, as it's unlikely that both will go bad. Try to vary the media types, for example for DVD don't use the same manufacturer for both copies, or use two hard drive, or one hard drive with DVD/Blu-ray copy.
The advantage of a large hard drive is that you can verify it regularly. Also, the SpinRite utility, available from http://www.grc.com/sr/spinrite.htm and costing $89, can recover a hard disk and even refresh it magnetically so the recorded data won't magnetically fade out with time (but it only works on internal drives).